I'm having an issue with my 2002 Suzuki Vinson500. After about 5-10 minutes of riding in high gear the H on the display will disapear and the bike will lose power, start to sputter and even backfire at times. If the H comes back then power seems to come back and were back in good shape. No issues at all in Low gear or reverse. Comes and goes when in high gear. My first thought is that it's electrical. Any thoughts?

 

Yes, electrical, but for it to affect the bike's running, it must be a dead short in the wire from the switch on the lever to the display.

 

It will run great for about the first 10-15 minutes. I took it out in the field behind my house and ran it for a bit. Kept it around 30 mph and after 10-15 minute it started acting up. The H on the screen would disappear and it would start to sputtering and lose power. Still electrical?

 

Yes, was the speedo part of the display disappearing as well? If it wasn't then it is something to do with the gear indicator circuit. If the speedo cuts as well, it could be a fault anywhere in the system, battery terminals, a faulty one will be getting warm, earth to frame, etc. Suzuki ignition switches are not the best quality but, if faulty, will usually start to work if you wiggle the key, or turn lights on.